Homo and Hetero-assembly of Inorganic Nanoparticles

This thesis describes the synthesis and assembly of metal and semiconductor nanoparticles (NPs). The two research topics include i) hetero-assembly of metal and semiconductor NPs, ii) effect of ionic strength on homo-assembly of gold nanorods (GNRs). First, we present hetero-assembly of GNRs and semiconductor quantum dots (QDs) in a chain using biotin-streptavidin interaction. We synthesized alloyed CdTeSe QDs and modified them with mercaptoundecanoic acid to render them water-soluble and to attach streptavidin. We synthesized GNRs by a seed-mediated method and selectively modified the ends with biotin. Hetero-assembly of QDs and GNRs depended on the size, ligands, and ratio of QDs and GNRs. Second, we controlled the rate of homo-assembly of GNRs by varying the ionic strength of the DMF/water solution. The solubility of polystyrene on the ends of GNRs depended on the ionic strength of the solution, which correlated with the rate of assembly of GNRs into chains.MAS

Thiol-ene chemistry for polymer coatings and surface modification : building in sustainability and performance

Future advancement of coatings relies on new synthetic building blocks and methods that enable added functionality, while minimising the environmental impact and cost. This review highlights the use of thiol-ene chemistry for surface modification and coatings, a topic of increasing interest in academic and industrial context since the beginning of this century. This chemistry platform has the advantages of rapid and uniform cross-linking, delayed gelation, reduced shrinkage, and insensitivity to oxygen. Recently, it resulted in significant advances in UV-cured coatings, including pigmented acrylate coatings and waterborne polyurethane dispersions. Moreover, biobased coatings were developed via thiol-ene coupling of unsaturated moieties in vegetable oils with multifunctional thiols, resulting in tunable properties. The homogeneous thiol-ene network formation has also been employed in hybrid coatings, yielding synergistic effects of the inorganic components within the thiol-ene matrix. Moreover, the UV-triggered thiol-ene reaction is fast and efficient, which is useful for surface modification with spatial and temporal control. In general, this review will critically describe how thiol-ene chemistry became a powerful tool for the sustainable development of functional coating materials and surfaces with a variety of building blocks

Precisely Alternating Functionalized Polyampholytes Prepared in a Single Pot from Sustainable Thiolactone Building Blocks

Polyampholytes with precisely alternating cationic and anionic functional groups were prepared using sustainable thiolactone building blocks in a simple one-pot procedure at room temperature and in water. Ring opening of the <i>N-</i>maleamic acid-functionalized homocysteine thiolactone monomer enabled the introduction of different functional groups into the polymer chain, which contributed to both ionic and hydrogen bonding interactions. The resulting polyampholytes exhibited various isoelectric points while maintaining high solubility in water under different pH and ionic strengths, which expands their potential applications. Finally, it is shown that the upper critical solution temperature (UCST) of these alternating polyampholytes in water/ethanol (30/70% vol) solutions can be tuned as a function of the content of ionic and hydroxyl groups